Efficacy of Single Dose Rasburicase (1.5 mg) for Prophylaxis and Management of Laboratory Tumor Lysis Syndrome

Rasburicase is a recombinant urate oxidase enzyme approved for use in tumor lysis syndrome (TLS) and it acts by reducing serum uric acid levels. Using rasburicase at the recommended dose of 0.2 mg/kg/day for 5 days is expensive and it is not known whether this extended schedule is clinically beneficial compared to a single fixed dose of 1.5 mg. The aim of the present study was to evaluate the efficacy of single dose rasburicase 1.5 mg in prevention and management of TLS. Rasburicase is available as single use 1.5 mg vial. At our institution a single dose of rasburicase 1.5 mg irrespective of bodyweight has been used in adults and in children a dose of 0.15 mg/kg (maximum 1.5 mg) has been used since 2012 for prevention and management of TLS and subsequent doses are given based on biochemical response and clinical condition. We retrospectively analysed the case records of patients who had received rasburicase from January 2012 to January 2017. The study included 186 patients with hematological malignancies who received rasburicase. Children accounted for 56.4% (n = 105) patients and males comprised 73% (n = 135). Rasburicase was used prophylactically in 59 (31.7%) patients, for laboratory TLS in 76 patients (40.8%) and for clinical TLS in 51 (27.4%) patients. Single fixed dose rasburicase prevented laboratory/clinical TLS in 87% of the prophylactic group and prevented clinical TLS in 72% of the laboratory TLS group. None of the patients in prophylactic and laboratory TLS group developed clinical TLS. However, majority of the patients with clinical TLS required more than one dose rasburicase. Single dose of 1.5 mg (1 vial) rasburicase is efficient in preventing and managing laboratory TLS and is economically viable in resource constrained settings.